Feature Overview

Before Cisco IOS Release 12.2(4)T, only the dialer idle timer could be reset for interesting traffic on a dialer interface. The Asynchronous Line Monitoring feature feature available in Cisco IOS Release 12.2(4)T supports a PPP idle timer based on interesting traffic for dialer interfaces. (Existing PPP idle timer behavior is not changed when traffic is not classified.) New commands and functionality provided with this feature also address idle timer issues for virtual access dialup network (VPDN) sessions, which use virtual access (projected) interfaces and rely on the PPP idle timer mechanism.

The Resource Pool Manager (RPM) per-customer profile dialer idle timer function works with Multilink PPP (MLP) and Multichassis Multilink PPP (MMP), providing that the master bundle interface is not a virtual access (projected) interface. For virtual access interfaces such as those used in a VPDN or with MMP where the dialer idle timer cannot be used, you can now classify the IP traffic that resets the PPP idle timer. A named access list is also supported.

Additionally, because RPM customer profiles are applied on a per-Dialed Number Identification Service (DNIS) basis and allow for configuring a per-customer profile dialer idle timer, the Asynchronous Line Monitoring feature feature associates idle timers based on call type and DNIS.

The idle timer implementation in the Asynchronous Line Monitoring feature feature specifies that for calls terminated on a network access server, a virtual access interface is cloned from the virtual template. This virtual access interface is linked to a physical interface on which is running a dialer timer. If the PPP idle timer is configured on the virtual template or provided by an authentication, authorization, and accounting (AAA) per-user interface configuration, the result is two idle timers, as follows:

•A PPP idle timer on the virtual access interface.

•A dialer idle timer on the physical interface.

Neither the dialer idle timer nor the PPP idle timer will run when the idle timer in the per-user configuration is set to 0. When the per-user idle timer is set to some value besides 0, that value overrides all local idle timer configurations.

Benefits

The Asynchronous Line Monitoring feature feature provides the following system idle timer benefits:

•Applies the user idle-timer value RADIUS attribute 28 across all interfaces associated with the call.

Restrictions

The PPP idle timer can classify IP traffic only.

Supported Platforms

See the next section for information about Feature Navigator and how to use this tool to determine the platforms and software images in which this feature is available.

Platform Support Through Feature Navigator

Cisco IOS software is packaged in feature sets that support specific platforms. To get updated information regarding platform support for this feature, access Feature Navigator. Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.

Feature Navigator is a web-based tool that enables you to quickly determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image.

To access Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions at http://www.cisco.com/register.

Feature Navigator is updated when major Cisco IOS software releases and technology releases occur. As of May 2001, Feature Navigator supports M, T, E, S, and ST releases. You can access Feature Navigator at the following URL:

http://www.cisco.com/go/fn

Supported Standards, MIBs, and RFCs

Standards

None

MIBs

None

To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL:

http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml

RFCs

None

Configuration Tasks

See the following sections for configuration tasks for the Asynchronous Line Monitoring feature feature. Each task in the list is identified as either required or optional:

Two Templates with Different Dialer Idle Timer Settings Example

The following partial example shows how to configure two customer profiles, each with different templates. Notice that each template sets the dialer idle timer differently:

resource-pool enable

!

resource-pool profile customer prf_cust_1

limit base-size all

limit overflow-size 0

dnis group dnis_g1

source template template1

!

resource-pool profile customer prf_cust_2

limit base-size all

limit overflow-size 0

dnis group dnis_g2

source template template2

!

template template1

dialer idle-timeout 45

dialer-group 1

!

template template2

dialer idle-timeout 90

dialer-group 2

!

dialer dnis group dnis_g1

number 11111111

!

dialer dnis group dnis_g2

number 22222222

Resetting the Dialer Idle Timer with Interesting Traffic Example

The following partial example shows how to configure an RPM customer profile that sets the dialer idle timer in a virtual template interface based on either inbound or outbound traffic:

resource-pool enable

!

resource-pool profile customer prf_cust_1

limit base-size all

limit overflow-size 0

dnis group dnis_g1

source template template1

!

template template1

dialer idle-timeout 45 either

dialer-group 1

!

dialer dnis group dnis_g1

number 1231231234

Network Access Server Extended Configuration Example

The following example shows the configuration for a Cisco AS5300 series access server, which is part of a large-scale dial-out configuration. Notice that on virtual template interface 1 the PPP idle timer is configured to reset only on interesting inbound traffic, and that both dialer interface idle timers are set to 60 seconds:

Glossary

interesting packets—Dialer access lists are central to the operation of DDR. In general, access lists are used as the screening criteria for determining when to initiate DDR calls.

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.Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.